Sleep loss is a common consequence of medical and psychological illness, as well as life style conditions (e.g., sleep restriction from shift work, jet lag, etc.), but its impact on affect has not been established. This study therefore aims to test the effects of sleep deprivation on behavioral and physiological manifestations of affective responses to emotion probes and performance stressors. It will also seek to identify neurobehavioral, psychological and demographic correlates of these responses. Healthy adult volunteers will spend two days in a laboratory facility. Subjects will be randomly assigned to either a sleep deprivation or control condition. On both days of the study, subjects' physiological and behavioral responses to emotion probes and psychosocial stressors will be measured. The hypothesis that sleep deprivation influences affect regulation will be tested using mixed model repeated measures ANOVA. Subjects' psychological and neurocognitive function will also be evaluated using validated tests and procedures. Relationships among these variables and affective responses will be tested using regression techniques. [unreadable] [unreadable] [unreadable]